Red to blonde?

I know someone has probably asked this before, but I'm a lazy witch and I can't be bothered reading every thread ever written .

Anyway I've got shoulder length red hair that's naturally very curly. What I'm looking for is to go mid to light blonde and have a longish straight bob. So can I do this without ruining my hair? And how often would I need to go back to the salon for roots and re-straightening?

Thanks if anyone bothers to reply to this

Sarah